SYNTHESIS AND PHOTOCHEMISTRY OF SUBSTITUTED PORPHYRINS

取代卟啉的合成及光化学

• 批准号: 3289790
• 负责人: JONATHAN SIDNEY LINDSEY
• 金额: $ 10.79万
• 依托单位: CARNEGIE-MELLON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1986
• 资助国家: 美国
• 起止时间: 1986-12-01 至 1989-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3289790
• 关键词: chemical structure function; chemical substitution; chlorin; chlorophyll; dimer; electron transport; p aminobenzoate; photochemistry; photosynthesis; porphyrin biosynthesis; quinones

Our long-term objectives are to develop synthetic methods for creating bioorganic molecules which can be used to provide insight into the relation between molecular structure and biological function. We have developed a room temperature biomimetic synthesis of tetraphenyl-porphyrin in 60% yield. We will expand the scope of this methodology to prepare porphyrins which have previously been unobtainable. This includes the class of meso-alkylporphyrins, some of which should be extremely soluble in lipid media. Amphipathic porphyrins can then be prepared for bilayer studies. Then we will exploit this new methodology in the high yield synthesis of cofacial dimers containing porphyrins and chlorins. We plan an extensive study of the electronic interactions resulting from the juxtaposition of rings. To model the light harvesting apparatus of photosynthesis, we will design and synthesize porphyrins bearing bulky substituents which in the crystalline state will hold the porphyrins at fixed distances apart. Fluorescence measurements in applied electric fields should provide data to distinguish the mechanisms of energy transfer. These new synthetic porphyrins should be of considerable value in extending our understanding of the properties of heme and chlorophyll in biological systems. A more global problem in bioorganic chemistry is the synthesis of model systems having well-defined 3-dimensional structures. We propose to create modular model systems of the photosynthetic process which contain a donor and acceptor covalently linked in a stacked geometry. The spacer groups separating the donor and acceptor are composed of p-aminobenzoic subunits, which are coupled together in a stepwise manner analogous to peptide and DNA synthesis. Three porphyrin-quinone compounds of 5, 10, and 15 A separation will be prepared which have 1, 2, and 3 subunits in their spacer groups. The photochemical characterization of this family of molecules will provide a systematic study of the effect of distances on electron transfer reactions. This modular approach should have broad applicability in the bioorganic field.

我们的长期目标是开发用于创建的合成方法 生物有机分子可用于提供有关关系的见解 分子结构和生物功能之间。 我们已经开发了室温的仿生合成 四苯基 - 卟啉的产率为60％。 我们将扩大此范围 制备以前无法获得的卟啉的方法。 这包括一类中烷基卟啉，其中一些应该是 在脂质培养基中极大地溶于作用。 两亲性卟啉可以是 为双层研究准备。 然后，我们将利用这种新方法 含卟啉和辅助二聚体的高产合成和 氯蛋白。 我们计划对电子相互作用的广泛研究 由环的并置。 建模光收集 光合作用的设备，我们将设计和合成卟啉 带有庞大的取代基，在结晶状态下将保持 卟啉在固定距离处分开。 应用的荧光测量 电场应提供数据以区分能量机制 转移。 这些新的合成卟啉应该具有很大的价值 在扩展我们对血红素和叶绿素特性中的理解时 生物系统。 生物有机化学中一个更全球的问题是模型的合成 具有明确定义的三维结构的系统。 我们建议创建 光合过程的模块化模型系统，其中包含供体 并在堆叠的几何形状中共价链接。 垫片组 分开供体和受体由p-氨基苯甲酸亚基组成， 以类似于肽和的逐步方式耦合在一起 DNA合成。 三种卟啉夸酮化合物为5、10和15 A 将制备其间隔中有1、2和3个亚基的分离 组。 这个分子家族的光化学表征 将对距离对电子的影响提供系统的研究 转移反应。 这种模块化方法应该具有广泛的适用性 在生物有机领域。